Last May I attended an international ­meeting on wind energy in Portugal, where 100 percent of that country’s electricity demand was met by renewable energy—a combination of solar, wind, and hydro—for four days. There have also been several short periods in which wind generation alone has exceeded 40 percent of demand in U.S. regional systems in places like Texas, Oklahoma, Kansas, Nebraska, and Colorado.

Some people think wind has value only in limited locations and will play a small role in meeting our overall energy needs (see “The One and Only Texas Wind Boom”). Instead, a history of cost reductions combined with decades of deployment and operating experience are bringing wind power to the cusp of transforming our electricity industry.

Yes, there are challenges. Wind is unlikely to ever be our sole source of electricity. Because the wind is variable, it creates some problems for the electric grid, but they’re not insurmountable. My organization has done studies that have looked into what would happen if wind and solar generated a third to a half or more of U.S. annual electricity demand, and we’ve found that there are ways to mitigate this natural variability by using flexible generators, such as natural gas or hydropower plants, and by coördinating operations over large geographic areas. In places like Denmark, Portugal, and Ireland, operators are already successfully managing the variable power generation that comes from wind and solar plants.

Thanks to research and development programs and policy incentives, the cost of wind has dropped by an order of magnitude since the early 1980s. Today there are long-term electricity price agreements in the U.S. supplying utilities with wind power at prices that are lower than operating costs for natural-gas plants, leveraged by technology advancements and favorable tax policy.

A recent survey of 163 industry experts found that the cost of wind energy is likely to drop 24 to 30 percent by 2030. They attribute this to a variety of technology, design, manufacturing, construction, and operational changes. Larger rotors, taller towers, and rotor design advancements should allow land-based wind technology to capture more energy at lower cost. Offshore wind technology will take advantage of larger turbines, better designs for foundations and support structures, and economies of scale through larger project size.

We’ve been waiting for low-carbon technologies to transform the power sector. We may finally be seeing it happen.

Maureen Hand is a senior engineer with the Strategic Energy Analysis Center of the National Renewable Energy Laboratory.